Introduction

This book has been written to highlight the remarkable progress in the application of botulinum toxin in medical practice. It is used across many specialties and has an increasing indication across a whole spectrum of diseases. As a result, its commercial sales have grown exponentially and its use in cosmesis has made ‘BOTOX®’ a household name. This is extraordinary after such a short time in this field and some other products have even gone so far as to add an ‘-ox’ on the end of their brand name to attempt to capture some of the kudos (and market) of botulinum toxin. This is of course very different from when the drug was first marketed and when it was regarded as a highly dangerous product. The indications for botulinum toxin treatment are listed in Chapter 5. In many, there is still little or no evidence that it works, but in others, there is good evidence of its therapeutic benefit.

History of BoNT

Botulinum toxin was first identified as a poison in the nineteenth century. The toxin is a protein, which is produced by the Gram negative Clostridium botulinum bacterium. It is found in a variety of foods, but is most common in meat products. The name botulus means sausage and hence its terminology from its appearance in meat products. The features of botulism have been known since around the time of Christ and it was certainly described in the Middle Ages.

Introduction

Spasticity is a physiological consequence of an insult to the brain or spinal cord, which can lead to life-threatening, disabling and costly consequences. This typically occurs in the following patients following stroke, brain injury (trauma and other causes, e.g. anoxia, post-neurosurgery), spinal cord injury, multiple sclerosis and other disabling neurological diseases, and cerebral palsy. Its current management has been advanced considerably over the last ten years by new thinking and by new drugs and technology. Lance's definition of 1980 is still relevant and the impairment is classified as one of the movement disorders. It is important therefore to stress when teaching on this topic, in order to highlight the need for patients' spasticity to be assessed while they are functioning. The fact that many attempts have been made to define it shows the degree of its complexity, but Young described spasticity as part of the upper motor neuron syndrome and gave a definition as a velocity-dependent increase in muscle tone with exaggerated tendon jerks resulting in hyper-excitability of the stretch reflex in association with other features of the upper motor neuron syndrome.

He also described spastic dystonia and spastic paresis, which are somewhat contentious terms, but do highlight the positive and negative features of the upper motor neuron syndrome and these are set out in Table 8.1. Essentially, if left untreated following damage to the brain or spinal cord, it is characterized by muscle overactivity and high-tone spasms and will lead to muscle and soft tissue contracture.